CN102797031B - Preparation method of pyrite-type ferrous disulfide nanoscale single-crystal semiconductor material - Google Patents

Abstract

The invention relates to a method for preparing a pyrite-type ferrous disulfide nanometer single crystal semiconductor material. The method comprises the following steps: (1) mixing an iron source with trioctyl phosphorus oxide, dissolving them in oleylamine, stirring and After passing argon or nitrogen to remove oxygen, the iron source precursor is obtained; (2) the iron source precursor is heated and stirred in an oil bath to obtain an iron source solution; (3) the sulfur source is dissolved in oleylamine, stirred and argon is passed or nitrogen to remove oxygen to obtain a sulfur source solution; (4) extract the sulfur source solution with a needle after being heated, and quickly inject it into the iron source solution, then heat up the oil bath for heating the iron source and react to obtain pyrite-type disulfide disulfide Iron colloid; (5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper layer of the centrifuge is colorless, and the washed sample can be sealed in chloroform solution. . The product obtained by the invention has uniform particle size and shape, good process repeatability and stable quality.

Description

A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material

technical field

The invention relates to a method for preparing a pyrite-type ferrous disulfide single crystal, in particular to a method for preparing a pyrite-type ferrous disulfide nanometer single crystal semiconductor material.

Background technique

Ferrous disulfide in nature exists in two forms of pyrite and marcasite. Pyrite-type ferrous disulfide is an excellent semiconductor material with a direct band gap of 0.95 eV, which is close to the requirement of 1.1 eV for ideal solar cell materials (A. Ennaoui, S. Fiechter, C. Pettenkofer, N. Alonso-Vante, K. Buker, M. Bronold, C. Hopfner and H. Sol. Tributsch, Iron disulphide for solar energy conversion [J]. Energy. Mater. Sol. Cells.1993, 29, 289-370.). Marcasite-type ferrous disulfide is an unstable variant of pyrite-type ferrous disulfide, and its direct band gap is 0.51 eV, which is too narrow to be used as a solar cell material. The optical absorption coefficient of pyrite-type ferrous disulfide is as high as 5*10 ⁵ , so the light absorption rate of pyrite-type ferrous disulfide with a thickness of 40 nm can be as high as 90% (Zhubing He, Shu-Hong Yu, Xiaoyuan Zhou , Xiaoguang Li and Jifeng Qu, Magnetic Field Induced Phase-Selective Synthesis of Ferrosulfide Microrods by a Hydrothermal Process: Microstructure Control and Magnetic Properties [J]. Adv. Funct. Mater. 2006, 16, 1105-1111.). According to the comprehensive analysis of 23 kinds of semiconductor materials by scientists, it is found that the potential power generation capacity of pyrite-type ferrous sulfide is higher than that of single crystal silicon, and it is an ideal photovoltaic material. In addition, pyrite-type ferrous disulfide can also be used in fields such as electrode materials for lithium-ion batteries. At the same time, due to its abundant reserves in nature, the cost is the lowest among the 23 materials, and the constituent elements of this material are non-toxic, which is very suitable for large-scale production (C. Wadia, A. P. Alivisatos, Materials Availability Expands the Opportunity for Large- Scale Photovoltaics DeploymentEnviron [J]. Sci. Technol. 2009, 43, 2072-2077.). However, ferrous disulfide in nature is mostly symbiotic with pyrite and marcasite, and the phase purity is not high enough, so it cannot be directly used as a solar cell material. It is necessary to artificially synthesize pure pyrite phase, uniform size and controllable ferrous disulfide. Iron nanocrystalline material, which is beneficial to the transport of carriers, reduces the recombination of carriers, and improves its photoelectric conversion efficiency.

At present, in order to avoid the oxidation of ferrous ions when synthesizing pyrite-type ferrous disulfide by wet chemical method, the hydrothermal method is usually carried out in two steps. First, the precursor iron-sulfur salt complex is synthesized, and then the hydrothermal reaction is carried out . This not only increases the steps of the reaction, but also the particle size of the prepared product is larger than 500 nm (Xianying Chen, Zhenghua Wang, Xiong Wang, Junxi Wan, Jianwei Liu, and Yitai Qian , Single-Source Approach to Cubic FeS ₂ Crystallites and Their Optical and Electrochemical Properties [J]. Inorganic Chem. 2005, 44, 951-954.; Cyrus Wadia, Yue Wu , Sheraz Gul, Steven K. Volkman, Jinghua Guo and A. Paul Alivisatos, Surfactant-Assisted Hydrothermal Synthesis of Single phase Pyrite FeS ₂ Nanocrystals [J]. Chem. Mater. 2009, 21, 2568-2570.). In the solvothermal preparation process, ethylene glycol is usually used as a solvent, and the size of the synthesized particles is relatively large (generally greater than 200 nm), or highly toxic solvents such as benzene are used (DW. Wang, QH. Wang and TM. Wang, Controlled growth of pyrite FeS ₂ crystallites by a facile surfant-assisted solvothermal method [J]. Cryst. Eng. Comm. 2010, 12, 755-761.; DW. Wang, QH. Wang and TM. Wang, Shape controlled growth of pyrite FeS ₂ crystallites via a polymer-assisted hydrothermal route [J]. Cryst. Eng. Comm. 2010, 12, 3797-3805.). The thermal injection method is an effective method for easily synthesizing monodisperse and highly fluorescent semiconductor nanocrystalline materials (ZT. Zhang, B. Zhao, and LM. Hu, PVP Protective Mechanism of Ultrafine Silver Powder Synthesized by Chemical Reduction Processes [J]. Journal of solid state chemistry, 1996, 121, 105-110.). Researchers have successfully synthesized CdTe, CdSe, CdS, ZnS by hot injection method (Celso de Mello Doneg, Peter Liljeroth and Daniel Vanmaekelbergh; Physicochemical Evaluation of the Hot-Injection Method, a Synthesis Route for Monodisperse Nanocrystal [J]. Small. 2005, 1(12), 1152-1162.; C. B. Murray, D. J. Norris and M. G. Bawendi, Synthesis and characterization of nearly monodisperse CdE (E= sulfur, selenium, tellurium) semiconductor nanocrystallites [J]. J. Am. Chem . Soc. 1993, 115, 8706-8715.; Juandria V. Williams, Nicholas A. Kotov and P. E. Savage, A Rapid Hot-Injection Method for the Improved Hydrothermal Synthesis of CdSe Nanoparticles [J]. Ind. Eng. Chem. Res . 2009, 48 (9), 4316-4321.; I. Sondi, O. Siiman, S. Koester and E. Matijevic, Preparation of aminodextran-CdS nanoparticle complexes and biologically active antibody-aminodextran-CdS nanoparticle conjugates [J]. Langmuir. 2000, 16, 3107-3118.) Monodisperse nanocrystalline materials. Law et al. prepared ferrous disulfide nanocrystals with spherical and ellipsoidal mixed morphology by hot injection method using octadecylamine and diphenyl ether as solvents (J. Puthussery, S. Seefeld, N. Berry, M.Gibbs and M. Law; Colloidal Iron Pyrite (FeS2) Nanocrystal Inks for Thin-Film Photovoltaics [J]. J. Am. Chem. Soc. 2011, 133, 716-719.). Jinsong Huang et al. used sulfur powder as the sulfur source to prepare cubic ferrous disulfide by thermal injection, but its grain size was larger than 100 nm (Y. Bi, YB. Yuan, C. L. Exstrom, S. A. Darveau and JO. Huang , Air Stable, Photosensitive, Phase Pure Iron Pyrite Nanocrystal Thin Films for Photovoltaic Application [J]. Nano Lett. 2011, 11, 4953-4957.). The hot injection method uses a high boiling point solvent, and at a higher reaction temperature, the precursor reactant solution is quickly injected into another phase reactant solution for reaction. This method has the advantages of easy synthesis of nanocrystalline materials with zero defects, small size and easy controllable morphology. At present, there is no report on the synthesis of pyrite-type ferrous disulfide single crystals with monodisperse, single-phase, and particle sizes around 50 nm using sulfide as a sulfur source.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing a pyrite-type ferrous disulfide nanometer single crystal semiconductor material with low cost and simple process.

In order to solve the above problems, the preparation method of a kind of pyrite type ferrous disulfide nano-single crystal semiconductor material of the present invention comprises the following steps:

⑴Mix the iron source and trioctylphosphine oxide (TOPO) at a molar ratio of 1:2~1:6, dissolve in oleylamine, stir and pass through argon or nitrogen with a purity of more than 98.5% to remove oxygen , to obtain an iron source precursor; the mass volume ratio of the iron source to the oleylamine is 1:100 to 1:300;

(2) heating the iron source precursor to 120-170°C in an oil bath and stirring for 0.5-1.5 hours to obtain an iron source solution;

(3) Dissolving the sulfur source in oleylamine, stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, to obtain a sulfur source solution; the mass volume ratio of the sulfur source to the oleylamine is 1:50~ 1:100;

(4) Heating the sulfur source solution to 60-90°C, then extracting it with a needle, and quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 180-220°C, and reacting for 1-3 hours , to obtain pyrite-type ferrous disulfide colloid; the volume ratio of the sulfur source solution to the iron source solution is 1:2 to 1:4;

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixed solution to wash and centrifuge until the upper layer of centrifugate is colorless, and the washed sample can be sealed in chloroform solution; The volume ratio of chloroform to ethanol in the chloroform-ethanol mixed solution is 1:0.5~1:1; the volume of the pyrite-type ferrous disulfide colloid and the chloroform-ethanol mixed solution The ratio is 1:2~1:5.

The iron source in the step (1) refers to ferrous chloride or ferrous sulfate whose concentration is 0.05 ~ 0.5 mol/L.

The sulfur source in the step (3) refers to any one of sulfur powder, thioacetamide, and L-cysteine monohydrate hydrochloride.

In the step (5), the mass concentration of ethanol in the chloroform-ethanol mixture is 50%.

Compared with the prior art, the present invention has the following advantages:

1. The present invention does not need the complicated two-step reaction of the hydrothermal method, does not use highly toxic solvents such as benzene, but uses a high boiling point solvent - oleylamine, and through the selection of different sulfur sources and iron sources, a large amount of monodisperse, A single-phase pyrite-type ferrous disulfide nanocrystalline material with a uniform cubic shape and a particle size of less than 100 nm.

2. The raw materials used in the present invention are cheap, therefore, the production cost is greatly reduced.

3. Compared with the existing thermal injection method, the preparation method of the present invention has the advantages of simple and convenient preparation process, short preparation time of the iron precursor, and a wide range of sulfur sources (not only sulfur powder can be used, but also thioacetamide, L- cysteine and other sulfur-containing compounds as sulfur sources), and for the first time synthesized monodisperse nano-cubic pyrite-type ferrous disulfide single crystals with a size of about 50 nm using sulfide as a sulfur source. The particle size of the synthesized products It has the advantages of controllability and shape.

4. The product obtained by the method of the present invention shows through X-ray diffraction analysis that it is a single-phase pyrite type ferrous disulfide (pyrite) (see Fig. 1, Fig. 6, Fig. 11), which is different from pyrite type ferrous disulfide. The peak position of ferrous sulfide (pyrite) standard PDF card 42-1340 is completely consistent.

5. The product obtained by the method of the present invention is analyzed by Raman spectrum, and it can be found that there is no Raman shift peak at 210, 280 cm ^-1 , which shows that there is no ferrous sulfide (FeS) in the synthesized material. The two strong peaks at 339,376 cm ^-1 on the spectrum are Raman characteristic peaks of ferrous disulfide. The results of the Raman spectrum further prove that the ferrous disulfide prepared by the hot injection method in the present invention is a single-phase pyrite type without other impurity phases (see Figure 16).

6. The product obtained by the method of the present invention is tested by ultraviolet-visible-near-infrared absorption spectrum, and it can be found that the sample in the visible light absorption region of 400 ~ 600 nm has better light absorption; its direct band gap is 0.90 eV, which is the same as The theoretical value of 0.95eV is relatively close, further indicating that the phase purity of the ferrous disulfide prepared by the present invention is very high (see Figure 17).

7. The product obtained by the method of the present invention is tested by X-ray diffraction, and it can be found that the prepared product is single-phase pyrite-type ferrous disulfide (see Figure 1, Figure 6, and Figure 11).

8. The product obtained by the method of the present invention is tested by scanning electron microscope, and it can be found that the prepared product is a monodisperse, more uniform cube shape pyrite type ferrous disulfide (see Fig. 2, Fig. 3, Fig. 7, Figure 8, Figure 12, Figure 13).

9. The product obtained by the method of the present invention is tested by transmission electron microscopy, and it can be found that the prepared product is a cubic pyrite type ferrous disulfide nano single crystal (referring to Fig. 4, Fig. 5, Fig. 9, Fig. 10, Fig. 14, Fig. 15).

10. The product obtained in the present invention has uniform particle size and shape, good process repeatability and stable quality, and is expected to be applied in the fields of photovoltaic conversion and lithium ion battery materials.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is the X-ray diffraction spectrum of the pyrite type ferrous disulfide prepared by sulfur powder of the present invention as a sulfur source.

Fig. 2 is a scanning electron micrograph of pyrite-type ferrous disulfide prepared with sulfur powder of the present invention as a sulfur source (the scale bar in the figure is 200nm).

Fig. 3 is a scanning electron micrograph of pyrite-type ferrous disulfide prepared with sulfur powder of the present invention as a sulfur source (the scale bar in the figure is 100nm).

Fig. 4 is a transmission electron micrograph of pyrite-type ferrous disulfide prepared with sulfur powder of the present invention as a sulfur source (the scale bar in the figure is 50nm).

Fig. 5 is a transmission electron micrograph of pyrite-type ferrous disulfide prepared with sulfur powder of the present invention as a sulfur source (the scale bar in the figure is 50nm).

Fig. 6 is an X-ray diffraction spectrum of pyrite-type ferrous disulfide prepared with thioacetamide as a sulfur source in the present invention.

Figure 7 is a scanning electron micrograph of pyrite-type ferrous disulfide prepared with thioacetamide as a sulfur source in the present invention (the scale bar in the figure is 200nm).

Fig. 8 is a scanning electron micrograph of pyrite-type ferrous disulfide prepared with thioacetamide as a sulfur source in the present invention (the scale bar in the figure is 100nm).

Fig. 9 is a transmission electron micrograph of pyrite-type ferrous disulfide prepared with thioacetamide as a sulfur source in the present invention (the scale bar in the figure is 50nm).

Fig. 10 is a transmission electron micrograph of pyrite-type ferrous disulfide prepared with thioacetamide as a sulfur source in the present invention (the scale bar in the figure is 10nm).

Fig. 11 is the X-ray diffraction spectrum of pyrite-type ferrous disulfide prepared by using L-cysteine monohydrate hydrochloride as a sulfur source in the present invention.

Fig. 12 is a scanning electron micrograph of pyrite-type ferrous disulfide prepared with L-cysteine monohydrate hydrochloride as a sulfur source in the present invention (the scale bar in the figure is 100nm).

Fig. 13 is a scanning electron micrograph of pyrite-type ferrous disulfide prepared with L-cysteine monohydrate hydrochloride as a sulfur source in the present invention (the scale bar in the figure is 100nm).

Fig. 14 is a transmission electron micrograph of pyrite-type ferrous disulfide prepared with L-cysteine monohydrate hydrochloride as a sulfur source in the present invention (the scale bar in the figure is 200nm).

Fig. 15 is a transmission electron micrograph of pyrite-type ferrous disulfide prepared with L-cysteine monohydrate hydrochloride as a sulfur source in the present invention (the scale bar in the figure is 100nm).

Fig. 16 is the Raman spectrum (a-sulfur powder; b-thioacetamide; c-L-cysteine monohydrate hydrochloride) of pyrite type ferrous disulfide prepared by different sulfur sources of the present invention.

Fig. 17 is a calculation diagram of the ultraviolet-visible near-infrared absorption spectrum and forbidden band width of pyrite-type ferrous disulfide prepared by using sulfur powder as a sulfur source in the present invention.

Detailed ways

Embodiment 1 A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material, comprises the following steps:

⑴Mix the iron source—ferrous chloride with a concentration of 0.05 mol/L and trioctylphosphine oxide (TOPO) at a molar ratio of 1:2, and dissolve in oleylamine, stir and pass the purity to 98.5% After removing oxygen from the above argon or nitrogen gas, an iron source precursor is obtained.

Among them: the mass volume ratio (g/ml) of iron source to oleylamine is 1:100.

(2) Heating the iron source precursor to 120° C. in an oil bath and stirring for 1.5 hours to obtain an iron source solution.

(3) Dissolve the sulfur source—sulfur powder in oleylamine, and after stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, obtain a sulfur source solution.

Among them: the mass volume ratio (g/ml) of sulfur source to oleylamine is 1:50.

(4) Heating the sulfur source solution to 60°C, then extracting it with a needle, quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 180°C, and reacting for 3 hours to obtain pyrite-type ferrous disulfide colloid.

Among them: the volume ratio of sulfur source solution to iron source solution (ml/ml) is 1:2.

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper centrifugate is colorless, and the washed sample can be sealed in chloroform solution.

Among them: the volume ratio (ml/ml) of chloroform to ethanol in the chloroform-ethanol mixture is 1:0.5; the mass concentration of ethanol in the chloroform-ethanol mixture is 50%. The volume ratio (ml/ml) of the pyrite-type ferrous disulfide colloid to the chloroform-ethanol mixture is 1:2.

Embodiment 2 A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material, comprises the following steps:

⑴Mix the iron source—ferrous chloride with a concentration of 0.5 mol/L and trioctylphosphorus oxide (TOPO) at a molar ratio of 1:6, and dissolve in oleylamine, stir and pass the purity to 98.5% After removing oxygen from the above argon or nitrogen gas, an iron source precursor is obtained.

Among them: the mass volume ratio (g/ml) of iron source to oleylamine is 1:300.

(2) Heating the iron source precursor to 170° C. in an oil bath and stirring for 0.5 hours to obtain an iron source solution.

(3) Dissolve the sulfur source—thioacetamide in oleylamine, and after stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, obtain a sulfur source solution.

Among them: the mass volume ratio (g/ml) of sulfur source to oleylamine is 1:100.

(4) Heating the sulfur source solution to 90°C, then extracting it with a needle, quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 220°C, and reacting for 1 hour to obtain pyrite-type ferrous disulfide colloid.

Among them: the volume ratio of sulfur source solution to iron source solution (ml/ml) is 1:4.

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper centrifugate is colorless, and the washed sample can be sealed in chloroform solution.

Among them: the volume ratio (ml/ml) of chloroform to ethanol in the chloroform-ethanol mixture is 1:1; the mass concentration of ethanol in the chloroform-ethanol mixture is 50%. The volume ratio (ml/ml) of the pyrite-type ferrous disulfide colloid to the chloroform-ethanol mixture is 1:5.

Embodiment 3 A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material, comprises the following steps:

⑴Mix the iron source—ferrous chloride with a concentration of 0.25 mol/L and trioctylphosphine oxide (TOPO) at a molar ratio of 1:4, and dissolve in oleylamine, stir and pass the purity to 98.5% After removing oxygen from the above argon or nitrogen gas, an iron source precursor is obtained.

Among them: the mass volume ratio (g/ml) of iron source and oleylamine is 1:200.

(2) Heating the iron source precursor to 140° C. in an oil bath and stirring for 1 hour to obtain an iron source solution.

(3) Dissolve the sulfur source—L-cysteine monohydrate hydrochloride in oleylamine, and after stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, obtain a sulfur source solution.

Among them: the mass volume ratio (g/ml) of sulfur source to oleylamine is 1:75.

(4) Heating the sulfur source solution to 75°C, then extracting it with a needle, quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 200°C, and reacting for 2 hours to obtain pyrite-type ferrous disulfide colloid.

Among them: the volume ratio of sulfur source solution to iron source solution (ml/ml) is 1:3.

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper centrifugate is colorless, and the washed sample can be sealed in chloroform solution.

Among them: the volume ratio (ml/ml) of chloroform to ethanol in the chloroform-ethanol mixture is 1:0.75; the mass concentration of ethanol in the chloroform-ethanol mixture is 50%. The volume ratio (ml/ml) of pyrite-type ferrous disulfide colloid to the chloroform-ethanol mixture is 1:3.5.

Embodiment 4 A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material, comprises the following steps:

⑴Mix the iron source—ferrous sulfate with a concentration of 0.05 mol/L and trioctylphosphine oxide (TOPO) at a molar ratio of 1:2, and dissolve in oleylamine, stir and pass the purity to more than 98.5% After removing oxygen from argon or nitrogen, the iron source precursor is obtained.

Among them: the mass volume ratio (g/ml) of iron source to oleylamine is 1:100.

(2) Heating the iron source precursor to 120° C. in an oil bath and stirring for 1.5 hours to obtain an iron source solution.

(3) Dissolve the sulfur source—sulfur powder in oleylamine, and after stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, obtain a sulfur source solution.

Among them: the mass volume ratio (g/ml) of sulfur source to oleylamine is 1:50.

(4) Heating the sulfur source solution to 60°C, then extracting it with a needle, quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 180°C, and reacting for 3 hours to obtain pyrite-type ferrous disulfide colloid.

Among them: the volume ratio of sulfur source solution to iron source solution (ml/ml) is 1:2.

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper centrifugate is colorless, and the washed sample can be sealed in chloroform solution.

Among them: the volume ratio (ml/ml) of chloroform to ethanol in the chloroform-ethanol mixture is 1:0.5; the mass concentration of ethanol in the chloroform-ethanol mixture is 50%. The volume ratio (ml/ml) of the pyrite-type ferrous disulfide colloid to the chloroform-ethanol mixture is 1:2.

Embodiment 5 A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material, comprises the following steps:

⑴Mix the iron source—ferrous sulfate with a concentration of 0.5 mol/L and trioctylphosphorus oxide (TOPO) at a molar ratio of 1:6, and dissolve in oleylamine, stir and pass the purity to more than 98.5% After removing oxygen from argon or nitrogen, the iron source precursor is obtained.

Among them: the mass volume ratio (g/ml) of iron source to oleylamine is 1:300.

(2) Heating the iron source precursor to 170° C. in an oil bath and stirring for 0.5 hours to obtain an iron source solution.

(3) Dissolve the sulfur source—thioacetamide in oleylamine, and after stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, obtain a sulfur source solution.

Among them: the mass volume ratio (g/ml) of sulfur source to oleylamine is 1:100.

(4) Heating the sulfur source solution to 90°C, then extracting it with a needle, quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 220°C, and reacting for 1 hour to obtain pyrite-type ferrous disulfide colloid.

Among them: the volume ratio of sulfur source solution to iron source solution (ml/ml) is 1:4.

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper centrifugate is colorless, and the washed sample can be sealed in chloroform solution.

Among them: the volume ratio (ml/ml) of chloroform to ethanol in the chloroform-ethanol mixture is 1:1; the mass concentration of ethanol in the chloroform-ethanol mixture is 50%. The volume ratio (ml/ml) of the pyrite-type ferrous disulfide colloid to the chloroform-ethanol mixture is 1:5.

Embodiment 6 A kind of preparation method of pyrite type ferrous disulfide nano single crystal semiconductor material, comprises the following steps:

⑴Mix the iron source—ferrous sulfate with a concentration of 0.3 mol/L and trioctylphosphorus oxide (TOPO) at a molar ratio of 1:4, and dissolve in oleylamine, stir and pass the purity to more than 98.5% After removing oxygen from argon or nitrogen, the iron source precursor is obtained.

Among them: the mass volume ratio (g/ml) of iron source and oleylamine is 1:200.

(2) Heating the iron source precursor to 150° C. in an oil bath and stirring for 1 hour to obtain an iron source solution.

(3) Dissolve the sulfur source—L-cysteine monohydrate hydrochloride in oleylamine, and after stirring and passing argon or nitrogen with a purity of more than 98.5% to remove oxygen, obtain a sulfur source solution.

Among them: the mass volume ratio (g/ml) of sulfur source to oleylamine is 1:80.

(4) Heating the sulfur source solution to 80°C, then extracting it with a needle, quickly injecting it into the iron source solution, then raising the temperature of the oil bath for heating the iron source to 200°C, and reacting for 2 hours to obtain pyrite-type ferrous disulfide colloid.

Among them: the volume ratio of sulfur source solution to iron source solution (ml/ml) is 1:3.

(5) When the pyrite-type ferrous disulfide colloid is cooled to room temperature, add chloroform-ethanol mixture to wash and centrifuge until the upper centrifugate is colorless, and the washed sample can be sealed in chloroform solution.

Among them: the volume ratio (ml/ml) of chloroform to ethanol in the chloroform-ethanol mixture is 1:0.7; the mass concentration of ethanol in the chloroform-ethanol mixture is 50%. The volume ratio (ml/ml) of the pyrite-type ferrous disulfide colloid to the chloroform-ethanol mixture is 1:4.

Claims (1)

1. a preparation method for Pyrite-type ferrous disulfide nano crystal semiconductor material, comprises the following steps:

(1) source of iron and trioctylphosphine oxide are pressed the mixed in molar ratio of 1:2 ~ 1:6, and are dissolved in oleyl amine, through stir and logical purity be more than 98.5% argon gas or nitrogen removing oxygen after, obtain source of iron presoma; Described source of iron and described oleyl amine mass volume ratio are 1:100 ~ 1:300; Described source of iron refers to that concentration is iron protochloride or the ferrous sulfate of 0.05 ~ 0.5 mol/L;

(2) described source of iron presoma be heated to 120 ~ 170 DEG C in oil bath and stir 0.5 ~ 1.5 hour, obtaining source of iron solution;

(3) sulphur source is dissolved in oleyl amine, through stir and logical purity be more than 98.5% argon gas or nitrogen removing oxygen after, obtain sulphur source solution; Described sulphur source and described oleyl amine mass volume ratio are 1:50 ~ 1:100; Described sulphur source refer in sulphur powder, thioacetamide, Cys one water salt hydrochloride any one;

(4) described sulphur source solution is heated to 60 ~ 90 DEG C, then extract with needle tubing, fast injection is entered in source of iron solution, then the oil bath of described heating source of iron is warming up to 180 ~ 220 DEG C, and reacts 1 ~ 3 hour, obtains Pyrite-type ferrous disulfide colloid; The volume ratio of described sulphur source solution and described source of iron solution is 1:2 ~ 1:4;

(5) when described Pyrite-type ferrous disulfide colloid being cooled to room temperature, add that trichloromethane-alcohol mixeding liquid carries out washing, centrifugal treating until upper strata centrifugate is colourless, the sample after washing is sealed in chloroformic solution; In described trichloromethane-alcohol mixeding liquid, the volume ratio of trichloromethane and ethanol is 1:0.5 ~ 1:1; The volume ratio of described Pyrite-type ferrous disulfide colloid and described trichloromethane-alcohol mixeding liquid is 1:2 ~ 1:5.